[vsnet-grb-info 15722] GRB 141031A, Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17010
SUBJECT: GRB 141031A, Swift-BAT refined analysis
DATE:    14/10/31 21:30:21 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings at nasa.gov>

T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),  W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings, N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC)
(i.e. the Swift-BAT team):
  
Using the data set from T-250 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 141031A (trigger #617110)
(Gompertz, et al., GCN Circ. 16995).  The BAT ground-calculated position is
RA, Dec = 128.632, -59.160 deg which is
    RA(J2000)  =  08h 34m 31.6s
    Dec(J2000) = -59d 09' 36.8"
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 32%.
  
The mask-weighted light curve shows three widely separated peaks.  The first
is a single symmetric peak from about T-20 to T+20 seconds, the second is
another symmetric peak ~20 sec long at about T+800, and the third is two
overlapping peaks from about T+850 to T+920 seconds.  T90 (15-350 keV) is
about 920 +- 10 sec (estimated error including systematics).
  
The time-averaged spectrum from T-22 to T+20 sec is best fit by a simple
power-law model with a power law index of 1.21 +- 0.13.  The time-averaged
spectrum from T+770 to T+920 sec is also best fit by a simple power-law model
with a power law index of 1.75 +- 0.18.  The total fluence for both intervals
in the 15-150 keV band is 2.9 +- 0.5 x 10^-06 erg/cm2.  The 1-sec peak photon
flux measured from T+5.08 sec in the 15-150 keV band is 0.5 +- 0.2 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.
  
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/617110/BA/